The present disclosure relates generally to surgical instruments for endoscopic, laparoscopic, or robotic surgery. Specifically, the present disclosure relates to surgical instruments comprising an end effector configured to staple tissue.
Surgical staplers are used to simultaneously make a longitudinal incision in tissue and apply lines of staples on opposing sides of the incision. Such instruments commonly include an end effector having a pair of cooperating jaw members that, if the instrument is intended for endoscopic or laparoscopic applications, are capable of passing through a cannula passageway. In one embodiment, one of the jaw members receives a staple cartridge having at least two laterally spaced rows of staples—one on each side of a knife channel defined therein. The other jaw member can define an anvil having staple-forming pockets aligned with the rows of staples in the cartridge. The instrument can also include a plurality of cam, or lift, surfaces that, when driven distally, pass through openings in the staple cartridge and engage drivers supporting the staples to effect the firing of the staples toward the anvil. Simultaneously, a cutting instrument (or knife) is moved distally along the jaw member so that the clamped tissue is cut and fastened (e.g., stapled) at the same time.
An example of a surgical stapler suitable for endoscopic applications is described in U.S. Pat. No. 7,000,818, entitled “Surgical Stapling Instrument Having Separate Distinct Closing and Firing Systems,” the disclosure of which is herein incorporated by reference in its entirety. In use, a clinician is able to close the jaw members of the stapler upon tissue to position the tissue prior to firing. Once the clinician has determined that the jaw members are properly gripping tissue, the clinician can then fire the surgical stapler, thereby severing and stapling the tissue. The simultaneous severing and stapling actions avoid complications that may arise when performing such actions sequentially with different surgical tools that respectively only sever or staple.
Surgical staplers are configured to be used in an optimal tissue thickness range. Presently, clinicians must use video feeds and intuition to determine if the thickness of tissue clamped in the end effector is within the optimal tissue thickness range. Developing a proper feel for the required thickness for a given cartridge type may take years of practice or may never occur for some clinicians. What is needed is a simple and reliable system for determining when the tissue clamped in an end effector is within the optimal tissue thickness range for a given staple cartridge.